Pneumatic pump



n. H. REEVES. PNEUMATIC PUMP.

APPLICATION FILED APR.24, 1919. 1,32,786,- Patented Oct. 24, 1922.

2 SHEETS-SHEET I.

INVENTQR Donald iLRceves ATTo R N BY Patented Oct. 24, 1922.

2 SHEETSSHEET 2.

D. H. REEVES;

PNEUMATIC PUM APPLICATION FILED APR. 24,19

Patented Oct. 24, 1922.

titan ar'r ris.

DONALD I-I. REEVES, OF DAYTON, OHIO.

PNEUMATIC PUMP.

Application filed April 24, 1919. Serial No. 292,319.

To aZZ whom it may concern: 1

Be it known that I, DONALD H. Rnnvns, a citizen of the United States,residing at 351 Edgewood Ave, Dayton, in the county of Montgomery andState of Ohio, have invented certain new and useful Improvements inPneumatic Pumps, of which the following is a specification.

This invention relates to a pneumatically operated gasoline pumpintended to be used in co-operation with the gasoline tank of anairplane.

It is desirable in airplane work to have the gasoline fed to the smallgravity tank, con1- monly located in the upper plane of an airplane, byair pressure. This has been done formerly by putting the whole gasolinetank itself under pressure. This is obviously obj ectionable, because asingle bullet hole through any part of the main tank would put thegasoline feed out of commission.

The principal object of this invention is to provide a means forpneumatically feeding the gasoline to the gravity tank withoutsubjecting the main gasoline tank to any higher pressure than theatmospheric pressure.

It is a further object of this invention to provide a gasoline pump thatis located in the bottom of the main gasoline tank, practically forminga sump, the gasoline flowing underthe influence of gravity alone intothe pressure chambers of the pump.

It is a further object of this invention to provide a gasoline pump inwhich two pressure chambers are provided, to which chambers air pressureis alternately admitted, and

then alternately vented. This alternate pressure-subjecting and ventingaction is auto 'matic in its operation.

Other objects and advantages will appear as the description proceeds,

In the drawings illustrating one embodiment of my invention, Figure 1 isa perspective vieW'of the assembled pump. F igure 2 is a similar viewwith the pump cover v removed. Figure 3 1s a plan view of the cover.Figure 4 is an enlarged'section taken on the line 4-4 of Figure 3.Figure 5 is a section, on a scale smaller than that of Figure 4, takenon the broken line 55 of Figure 3. Figures 6 and 7 are diagrammaticsectional views to illustrate the operation of the reversing valve.Figure 8 is an enlarged sectional-view taken on a vertical plane passingthrough the line 88 of Figure 1.

Figure 9 is a reduced view partly in elevation and partly in section,showing the relation of the pump to the gasoline tank.

The pump comprises a main body element 1 which is divided by thepartition 2 into the floatpressure chamber 3 and the auxiliary pressurechamber 4:. An escape pipe 5 for the gasoline is provided with branches6 and 7 that are bolted, by bolts 6 and 7', to plates 8 011 the side ofthe casing 1, to register with appropriate openings from the twopressure chambers 41 and 3, respectively. Each of the plates 8 carriesan opening 8 that is controlled by the disk 9 being pressed thereover bythe spring 10, thus forming a one way valve. Each plate 8 may beprovlded with a lip 11 extended downwardly so that when air pressure isadmitted to the chamber 4 gasoline will be drained or forced from thechamber as far down as the lower level of the lip.

The cover plate 12 is secured by a plurality of screws 13 to body 1 tocomplete the pressure chambers 3 and 4:. This cover plate is providedwith the gasoline inlet pipes 14 and 15, that open respectively into thepressure chambers 4t and 3, each being controlled by one way valves 16,mounted loosely on pins 17 to move outwardly. Only one of these is shownin Figure 8. The other not shown, is precisely similar.

Mounted on the cover plate 12, preferably over t-he main pressurechamber 3, is a float chamber comprising avertical, cylindrical wall 18,and a top plate 19. The wall 18 is flanged as at 18, for securement tothe cover plate 12, the cover plate 12 being cut away just below thefloat chamber so that the interior thereof is in communication with theinterior of the float chamber.

Mounted in the top wall 19 of the float chamber is a valve mountingcasting 20 which is provided with a series of air pressure and air ventpassages. A vertically disposed cylindrical passage 21 is drilled in thecasting 20, the passage 21 being open at its lower end into the floatchamber. A horizontally drilled passage 22 communicates with the passage21 at its upper end to also communicate with the float chamber.

The casting 20 has drilled therein passages 23 and 21 which, through thehole 25 are in communication with the passage 21 at the point shown. Areversing valve, comvalve disc 27 carried by a valve stem 28 is movablein the valve passage 21. It should be noted that the disc 26 when in itsuppermost positionis just below the opening 22 and that at the same timethe disc 27 is just below the opening 25.

Referring now to Figure 5, casting 20 is also provided with a passage29, for the admission of air. Passage 29 is in communi cation withpassage 21, through the hole 30. The hole 30, it should be noted, isbelow the valve disc 27 when the valve is inits uppermostposition. Thevalve is shown in its uppermost position in both Figures 4 and Referringto Figure 5, casting 20 is further provided with the vent passage 31,which through the hole 32 is in communication with the valve passage 21,at a point below the valve disc 26 when in its uppermost position. 7

An air pressure pipe 33 leads compressed air to the top of the floatchamber and into the air passage 29. A short pipe 33, projects to theoutside of the body 1, and registers with pipe 33. A compressed airpipe, not shown, is attached to A pipe 34 thatat one end 35 communicateswith the auxiliary pressure chamber 4, at its other end 34 connnunicateswith the already described passages 23 and 24. The vent passage 31 is incommunication with a vent pipe indicated by dotted lines at 36 inFigure 1. This pipe 36 passes upwardly through the gasoline in which thepump is immersed and opens into the top of the gasoline tank.

The casting 20 is provided with downwardly extending arms, one of whichis indicated at 37, which carry at their lower ends a disc 38, providedwith an aperture 39 in which aperture the lower end of the valve stem 28is slidable up and down; The valve stem 28 is provided, toward its upperend with a flange 40 and toward its lower end with a shoulder 41, thatis screw threaded on the valve stem.

A sheet metal float 42, annular in form surrounds the casting 20 andpart of the standard 37 loosely so as to be slidable up and down withrespect to said standard. Suitably secured to the inner wall 43 of thefloat is a bracket 44 provided with a hole 45, through which hole thevalve stem 28 passes with'a loose fit. Springs 46 and 47 arerespectively positioned between the flange 40 and bracket 44, and thebracket 44 and shoulder 41. i

A latch element 48 provided with an up- I per latching shoulder 49 and alower latching shoulder 50, is carried by the arm 51, which is mountedat its lower end 52 in the disc 38 so as to have a slight lateralmovement. The arm 51 is provided with a bevel portion 53, a straightportion 54, and a reversely beveled portion 55. A spring 56, mounted onthe standard 37 by rivets 57,

presses against the arm 51 to press it to the left of Figure 4.

The pump of this invention is designed to be mounted in the bottom of agasoline tank and acts practically as the sump thereof. The pump is heldin the bottom of the tank by suitable bolts or screws passing throughthe flange 58. The cover plate 12 and float chamber 18 and associatedparts are completely immersed in gasoline.

The operation of the device will now be described. With the valvepositioned as in Figures 4, 5 and 6, the pressure chamber 3 presumedfull of gasoline that has flowed in by ravity through the pipe 15, thefloat will of course be in its uppermost position as shown in Figure 4.With the valve also in its uppermost position, it is apparentthat airpressure will be admitted through the aperture 30 to the interior of thefloat chamher. This air pressure will force the gasoline in the chamber3, out through the pipes 7 and 5 up to the gravity tank, not shown, orother desired point. 'At the same time itshould be noted that theauxiliary chamber 4 is in communication with the vent 32 through thehole 25, passages 24 and 23 and pipe 34. While then the air pressure isforcing gasoline out of the chamber 3 the gasoline is flowing into thechamber 4 through the inlet pipe. 14, the air that it displaces escapingthrough the pipe 34 and vent 32 and pipe 36 into the top of the gasolinetank.

As the gasoline leaves the chamber 3 the float 42 gradually falls. Thelatching shoulder 49 however during this operation holds the valve stem28 in the-uppermost position as shown in Figure 4. As the float falls itcarries with it the bracket 44, which rides over the beveled portion 53,straight portion 54 and onto the beveled portion 55', until finally itforces the arm 51 to the right. During its downward movement the bracket44 continually compresses the spring 47 and releases spring 46. By thetime that the bracket 44 has reached the bevel portion 55, the spring 47is rather tightly compressed and spring 46 relieved. At this instant thelatch 48 will be forced so far to the right as to disengage from'theshoulder 40 whereupon the spring 47, acting on the shoulder 41, willmove the valve stem '28 quickly downwardly so that it reaches theposition passage 22 will be in communication with the vent 32, so thatthe air may escape from the float chamber through the vent pipe 36 tothe top of the tank. This relieves the air pressure in the floatchamber, whereupon it will fill by gasoline flowing into it through theinlet 15 under the influence of gravity alone.

At this point it should be stated that the 1 valve stem 28 is held inits lowermost position,

as shown in Figure 7 by the latching shoulder 50 having engaged over thetop of the flange 40. As the gasoline flows into the chamber 3 the float42- starts to rise again. As the float rises the bracket 44 passes overthe straight portion 54 of the latch member 51 and onto the beveledportion 53, it during this upward movement putting the spring 46 undercompression and releasing spring 47. By the time that the bracket 44 hasgotten well onto the bevel portion 53 the spring 46 is fairly wellcompressed. Continued upward movement of the float and bracket 44 causesthe latch 51 to be moved to the right to unlatch the shoulder 50 fromthe flange 40, where upon the spring 46 will move the'valve stem 28 backto the position shown in Figures 4 and 6, which causes the cycle ofoperations to start over again. This valve reversing means andalternately filling and emptying of the two pressure tanks is entirelyautomatic in its action.

lVhile I have illustrated my invention in considerable detail, it shouldbe understood that it may be carried out in many other Ways as definedwithin the scope of the following claims.

I claim 1. In combination with a closed in main fuel tank, an auxiliaryfilling chamber in communication with said tank, and fed by gravity fromsaid tank, a valve to control the flow of fuel from said main fuel tank,means for emptying the fuel from said filling chamber, a floatcontrolled means in said filling chamber for automatically communicatingsaid filling chamber with the top of said main fuel tank, said floatcontrolled means comprising an energy storing spring device operated bysaid float and held by a latch, said latch being automatically releasedby a cam controlled by the float of said float controlled means.

2. In combination with a closed in main fuel tank, an auxiliaryflllingchamber in communication with said tank, and fed b gravity fromsaid tank, a valve to control the flow of fuel from said main fuel tank,pneumatic means for emptying the fuel from said filling chamber, and afloat controlled means in said filling chamber for automaticallycommunicating said filling chamber with the top of said fuel tank, saidfloat controlled means comprising an energy storing spring deviceoperated by said float and held by a latch, said latch beingautomatically released by a cam controlled by the float of said floatcontrolled means.

In testimony whereof I affix my signature.

DONALD H. REEVES.

